New Delhi: On July 23, 2025, the International Court of Justice (ICJ), the United Nations’ highest judicial body, delivered a groundbreaking advisory opinion that marks a turning point in global climate action. The ruling, issued at the Peace Palace in The Hague, Netherlands, establishes that countries failing to address climate change may violate international law, potentially entitling affected nations, particularly vulnerable Small Island States (SIDs), to seek reparations. Led by the Pacific island nation of Vanuatu and backed by over 130 countries, this unprecedented case sets a new legal precedent for climate accountability and reinforces the urgent need for nations to act decisively to combat the climate crisis.
The Genesis of the Case
The case originated from years of advocacy by vulnerable island nations, particularly those in the Pacific, who face existential threats from rising sea levels due to climate change. In 2019, a group of young law students from these low-lying islands, including Siosiua Veikune from Tonga, proposed seeking an advisory opinion from the ICJ. Their efforts culminated in 2023 when the UN General Assembly adopted a resolution requesting the ICJ to clarify two critical questions:
- What are states’ obligations under international law to protect the climate and environment from human-caused greenhouse gas (GHG) emissions, both now and for future generations?
- What are the legal consequences for states whose actions, or lack thereof, significantly harm the climate and environment, particularly for vulnerable island states?
The case, described as the ICJ’s largest ever, involved tens of thousands of pages of written submissions and two weeks of oral arguments in December 2024. Representatives from Pacific Island nations, including Vanuatu’s Attorney General Arnold Kiel Loughman and Minister for Climate Change Ralph Regenvanu, emphasized the dire stakes, noting that the survival of their people is at risk.
Key Highlights of the ICJ Ruling
The ICJ’s 500-page advisory opinion, delivered unanimously by a panel of 15 judges led by President Yuji Iwasawa, provides a comprehensive framework for climate obligations under international law. The ruling addresses several critical points:
1. Clean, Healthy, and Sustainable Environment as a Human Right
The ICJ declared that a “clean, healthy, and sustainable environment” is a fundamental human right, grounded in treaties like the Universal Declaration of Human Rights. This landmark recognition paves the way for future legal actions, including domestic lawsuits and international claims, to hold states accountable for climate inaction. It also strengthens the legal basis for individuals and nations to demand protection from climate-related harms, such as rising sea levels, extreme weather events, and ecosystem degradation.
2. States’ Obligation to Limit Greenhouse Gas Emissions
The court ruled that states are legally obliged to prevent harm from GHG emissions and to align their actions with the Paris Agreement’s target of limiting global warming to 1.5°C above pre-industrial levels. With global temperatures already having risen by 1.3°C, the ICJ emphasized the urgency of reducing emissions to protect vulnerable populations and ecosystems. The ruling rejected arguments from major emitters like the United States and the United Kingdom, who claimed that existing climate treaties, such as the 2015 Paris Agreement, were sufficient without additional legal obligations. The ICJ clarified that broader international law applies, meaning even countries not bound by the Paris Agreement—or those considering withdrawal, like the US—are still required to protect the environment.
3. Legal Consequences for Non-Compliance
The ICJ outlined clear consequences for states that fail to meet their climate obligations. Such failures may constitute an “internationally wrongful act,” triggering legal responsibilities, including:
- Ceasing wrongful conduct.
- Offering guarantees of non-repetition.
- Providing full reparation for damages, depending on the circumstances.
The court noted that attributing specific climate harms to individual states could be complex but affirmed that nations harmed by climate change, such as SIDs, have a right to seek compensation for impacts like destroyed infrastructure or forced relocation. For instance, the Marshall Islands highlighted adaptation costs of $9 billion—a sum they cannot afford—for a problem they did not cause.
4. Historical Responsibility and Fossil Fuel Accountability
The ICJ emphasized that industrialized nations, as the largest historical emitters, bear a greater responsibility to lead climate action. The court also ruled that governments are accountable for the climate impacts of companies operating within their jurisdictions. Actions such as subsidizing fossil fuel industries or approving new oil and gas licenses could breach international obligations. This finding strengthens the case for holding polluters accountable for both past and present emissions.
Global Reactions and Implications
The ICJ’s ruling was met with widespread celebration among climate activists and vulnerable nations. Outside the packed courtroom, supporters gathered with banners proclaiming, “Courts have spoken. The law is clear. States must ACT NOW.” After the ruling, climate campaigners were seen laughing and hugging, reflecting the emotional weight of the decision.
“This is a victory not just for us but for every frontline community fighting to be heard,” said Flora Vano from Vanuatu, the country most vulnerable to extreme weather globally. Siosiua Veikune, one of the Tongan students who initiated the case, expressed overwhelming joy, stating, “This is a win we take proudly back home to our communities.”
Environmental organizations, such as Oxfam and Greenpeace, hailed the ruling as a transformative moment. Nafkote Dabi, Oxfam’s climate change policy lead, emphasized that the decision “elevates national climate commitments everywhere” and mandates faster emission cuts, particularly from wealthy nations. Danilo Garrido of Greenpeace International called it the “start of a new era of climate accountability,” urging polluters to stop emitting and pay for the harms caused.
However, opposition persists from major emitters like the United States and Russia, both significant petroleum producers, who have resisted court-mandated emission reductions. A White House spokesperson reiterated a commitment to “putting America first,” while the UK’s Foreign, Commonwealth and Development Office stated it would review the ruling before commenting further, emphasizing existing UN climate treaties.
Broader Legal and Political Context
The ICJ ruling builds on a series of legal victories for climate justice. Earlier in July 2025, the Inter-American Court of Human Rights ruled that countries have a duty to avoid environmental harm and restore ecosystems. In 2024, the European Court of Human Rights mandated better protection from climate impacts, and in 2019, the Netherlands’ Supreme Court recognized climate protection as a human right. These decisions collectively strengthen the global legal framework for climate action.
The ICJ’s opinion, while non-binding, carries significant legal and political weight. Previous ICJ advisory opinions, such as the UK’s agreement to return the Chagos Islands to Mauritius, have influenced state behavior. Legal experts, including Joie Chowdhury from the Centre for International Environmental Law, predict the ruling will be cited in national and international courts as early as the following week. Developing nations are already exploring new cases to seek compensation for historical emissions, potentially targeting courts where major emitters like the US are bound, such as US federal courts.
Challenges and Limitations
Despite its significance, the ICJ ruling faces challenges. The court acknowledged that international law plays a limited role in resolving the climate crisis, which President Iwasawa described as “an existential problem of planetary proportions.” A lasting solution will require contributions from all fields of knowledge. Additionally, the ICJ lacks enforcement mechanisms, relying on states’ willingness to comply. As climate barrister Harj Narulla noted, the ICJ is “subject to geopolitics” and cannot force adherence.
Determining specific damages for climate impacts, such as linking a single extreme weather event to climate change, remains complex. However, the court clarified that compensation could be sought for broader impacts, such as rising sea levels, which have already caused significant losses. For example, a 2015 cyclone in Vanuatu destroyed 276,000 homes and wiped out two-thirds of its GDP, while global climate losses between 2000 and 2019 are estimated at $2.8 trillion.
The Role of the Paris Agreement
The ICJ emphasized the importance of the 2015 Paris Agreement, which commits over 190 countries to limit global warming to 1.5°C. The court ruled that nationally determined contributions (NDCs) must reflect the “highest possible ambition” to meet this target. However, current climate policies are projected to result in warming exceeding 3°C by 2100, highlighting the gap between commitments and action. The ruling strengthens the legal obligation for countries to enhance their NDCs and phase out fossil fuels, particularly in wealthy nations.
Vanuatu’s Leadership and Global Solidarity
Vanuatu’s leadership in this case underscores the power of small nations to drive global change. Supported by over 130 countries, including many developing nations frustrated by the slow pace of climate action, Vanuatu’s efforts highlight the disproportionate impact of climate change on those least responsible. The ruling also aligns with calls for South-South climate cooperation, with countries like India potentially playing a role in supporting vulnerable nations.
A New Tool for Climate Justice
The ICJ’s decision provides a “powerful new tool” for climate justice, as described by former UN human rights chief Mary Robinson. It affirms that those least responsible for the climate crisis, such as Pacific Island nations, deserve protection, reparations, and a future. As Vishal Prasad from Pacific Islands Students Fighting Climate Change stated, the ruling brings the world closer to a reality where governments can no longer ignore their legal responsibilities.
In conclusion, the ICJ’s landmark ruling on July 23, 2025, marks a historic moment in the fight against climate change. By establishing climate protection as a human right, mandating emission reductions, and opening the door for reparations, the decision sets a new standard for global accountability. While challenges remain, particularly in enforcement and geopolitical resistance, the ruling empowers vulnerable nations and climate advocates to pursue justice through legal avenues worldwide, ensuring that the fight for a sustainable future continues with renewed urgency.
Frequently Asked Questions (FAQs)
1. What is the ICJ’s ruling on climate change about?
The International Court of Justice (ICJ) delivered an advisory opinion on July 23, 2025, stating that countries failing to address climate change may violate international law. The ruling, prompted by Vanuatu and supported by over 130 nations, clarifies states’ obligations to reduce greenhouse gas emissions, protect the environment as a human right, and provide reparations for climate-related harms, especially to vulnerable Small Island States.
2. Is the ICJ’s climate change ruling legally binding?
No, the ICJ’s ruling is an advisory opinion and not legally binding. However, it carries significant legal and political weight, influencing international and domestic legal actions. It sets a precedent for holding states accountable and can be cited in courts globally to demand climate action and compensation.
3. What are the key obligations for countries under this ruling?
The ICJ ruled that countries must limit greenhouse gas emissions to meet the Paris Agreement’s 1.5°C target, protect a “clean, healthy, and sustainable environment” as a human right, and take responsibility for historical emissions. Industrialized nations, as major emitters, have a greater obligation to lead, and actions like subsidizing fossil fuels may breach international law.
4. How does the ruling impact vulnerable nations like Vanuatu?
The ruling empowers vulnerable nations, particularly Small Island States like Vanuatu, by affirming their right to seek reparations for climate damages, such as rising sea levels and extreme weather. It provides a legal framework to hold high-emitting countries accountable, potentially through international or domestic courts, for losses like Vanuatu’s $2.8 trillion in climate damages from 2000–2019.
5. What are the challenges in implementing the ICJ’s ruling?
Implementation faces challenges due to the non-binding nature of the ruling, geopolitical resistance from major emitters like the US and Russia, and the complexity of attributing specific climate harms to individual states. The ICJ lacks enforcement mechanisms, relying on states’ voluntary compliance, and global cooperation across all fields is needed for lasting solutions.
